Silverfish Facts and FAQs: What You Need to Know to Fight the Good Fight

If you’re perusing the Internet for silverfish facts, it’s likely there’s been a sudden increase in the legs to opposable thumbs ratio in your home. You may be walking on eggshells, with your eyes resolutely on the horizon, in case you spot yet another silverfish crawling through your kitchen like a casual commuter.

If so, worry not. You’re one of us. Many of us are paralyzed with squeamishness and irritation at many-legged home invaders, with no idea what we’re up against.

But, now you’re in safe hands; sift through our in-depth list of silverfish facts and FAQs and better equip yourself to get rid of the pests once and for all!

What are silverfish bugs?

Let’s start at the beginning, shall we? Just what are silverfish? The more observational among you will have noticed that there aren’t any large bodies of water in your home – so the humble silverfish clearly isn’t an actual fish.

Silverfish are fairly conventional little insects, nocturnal in nature, which get their name due to the way they look and the strange fish-like shifting pattern of their walk.

Fun fact: they’re actually believed to be one of the oldest insects on the planet, existing for somewhere around 400 million years in their current form!

What do silverfish look like?

Conventional wisdom would have you believe that they look like very, very small fish; and they do at a glance. Look a little closer, however, and you’ll see that the critters are not unlike some more common leggy insects or arachnids.

Their abdomens taper into a fine point towards their back legs and the silverfish skin color tends to orbit around a light blue-ish, silver shade, which obviously gives them their name. That said, how many fish have you seen with antennae?

Average sizes for silverfish are between half an inch to just under an inch, when fully grown; but hey, a small insect can cast a large shadow for the squeamish out there!

They’re flightless bugs and lack any of the wall-climbing apparatus of other creepy crawlies like spiders, beetles, some scorpions etc. Instead, they rely solely upon their cross-country running prowess… if you’ve ever experienced a silverfish first hand, you know what I mean. They’re lightning quick when they need to be.

Where do silverfish come from?

If you’re wondering whether silverfish are just more common in certain countries and areas – yes, they kind of are although they don’t have to be.

Silverfish are surprisingly hardy little creatures and are more than capable of surviving in a great variety of different environments and climates. They much prefer places with humid weather and atmosphere, however, as this is the optimum condition for longevity, food, reproduction and maturity.

Generally, the damper and warmer the weather is in your country or area, the more likely it is that you pose as a nice attraction for any local silverfish to set up shop.

What do silverfish eat?

Silverfish are basically the insect equivalent of your weird pal with the weird obsession with weird diets. You know the one.

Technically, they’re omnivores, but silverfish tend to favor things that are very high in starch, protein or polysaccharides (found in things like adhesives and glues). This goes some way to explaining why they’re often found nibbling on books, bindings, papers, photos, sugary food deposits and, disgustingly, things like human hair and dead skin.

On a slightly more regular basis, the carbohydrate substance of things like flour, cereals, oats can attract the hungry bugs, as well as even other dead insects or leathers if they’re truly in dire straits for a wholesome meal – kind of bizarre for a creature that will literally suck the urine out of stained clothing if it can, but there you go. Different strokes for different folks.

Do silverfish eat wood?

A common question asked of silverfish is whether they eat wood or not. The answer is no, they’re not known to have any wood in their diets – if you’re noticing wooden furniture or interiors that look like they’re suffering damage, it’s much more likely that you have a termite problem.

Do silverfish eat clothes?

As you might’ve noticed by now, silverfish aren’t the pickiest eaters. And yes, they do and will eat clothes…but it’s not their first choice.

It’s worth noting, though, that silverfish tend to favor lighter fabrics when they have a hankering for your clothing so they’re most likely to nibble on cottons, linens and silks. If you’re noticing damage in heavy, wintry clothing then you might be dealing with a different beasty!

How often do silverfish need to eat?

Although one of the go-to tactics for ridding your home of an insect or bug infestation is to eradicate the pests’ food source as soon as possible, it can prove to be a little more difficult where silverfish are concerned.

This is because the stubborn creatures have evolved to have low metabolisms, which mean that in some truly extreme situations, they can get by on as little as one meal per year.

They won’t suffer these conditions willingly, however. The less ample food is on offer to them, the more likely they are to start feeding on other insects or even get desperate enough to chow down on leather materials.

The joys of not being a fussy eater, eh?

Where do silverfish live?

Silverfish are not unlike cockroaches in their choice of environment and physical makeup. Both creatures are fairly small, tactile and squeeze their frames into ridiculously tight spaces for shelter or because they’ve detected some food source.

With this in mind, silverfish tend to favor environments that are humid, moist, peaceful (away from predators or the giant lumbering behemoths of human beings) and, above all, somewhere close by a reliable food source. Find out what attracts silverfish!

Much like most creepy crawlies, silverfish are often found in basements, bathrooms, bathtubs, kitchens and so on: somewhere close to pockets of moisture and around leaky pipes. They’re just like spiders, however, in that they’re unable to climb up the porcelain of a bathtub, which makes for easy disposal.

Remember that they’re nocturnal creatures, so a silverfish problem may go undetected for quite some time until more noticeable issues arise: usually this will be things like feeding on your books, adhesives, papers, boxes and clothing… and where do you often store old things? In the attic.

It might be worth spending a little time doing some searching for yourself and perhaps airing out old stored materials or clothing just to be sure you don’t have any insect issues festering unbeknownst to you.

Are silverfish harmful?

Luckily for us, silverfish aren’t actually harmful to humans or pets – aside from the initial visceral shock or fear of stumbling across one, that is. They also do not carry diseases and, despite how common they might seem at times, are quite reluctant and shy critters.

Are silverfish poisonous?

No, they may be gross-looking but thankfully, they’re not poisonous. Often, due to their appearance, silverfish can be mistaken for some more venomous strains of centipedes; some of which can be a danger or risk to humans if they bite.

Do silverfish bite?

As noted above, they tend to be quite reticent around humans and would much prefer to run away like a pansy than stay and fight their corner, so they generally don’t bite humans.

That’s not to say that silverfish bites haven’t been reported in the past, however.

Should one manage to sink its gnashers in to your hand or elsewhere, it’s not a cause for concern. It may sting a little and perhaps show up as red or tender, but you’re unlikely to suffer any other side effects or risks.

What do silverfish do?

A lot of people ask this question, seeing as silverfish can start to seem like fairly magnanimous creatures that don’t pose much of a threat or disturbance. I mean, they essentially eat, hide and hang out.

So the question of silverfish damage and the lengths you should go to to rid yourself of them is pretty subjective.

Some folk might not care if they have to squish (or rather, hopelessly chase) the odd silverfish, but a lot of homeowners find themselves googling emigration laws for tamer countries at the first sight of antennae…or so I hear.

That said, if you have an infestation of them or a particularly hardy one has found its way into either your clothing, food reserves or books and papers – it can be a huge pain. Clear signs of silverfish activity are yellowish stains from their body, small holes here and there in paper or books and, sorry, fecal droppings.

What is the silverfish life cycle?

The average time of maturation for silverfish can be anywhere from three months to two years and the birth dates and rates of the eggs can change depending on a number of different aspects such as environmental temperature and the species of the silverfish itself.

Unlike the majority of insects and, indeed, wider spectrum of animals; female silverfish are able to lay eggs all year round, without having to wait for a specific time of the year and given that they can lay several eggs per day… A problem can quickly arise in the right environment.

The actual life cycle of the average silverfish goes like this…

Silverfish Egg Stage

Of course, they begin in their eggs which are usually laid in very quiet, cramped and sheltered spaces – the damper, the better. If temperatures and climate are ideal, the eggs can take as little as a few weeks to hatch.

50 degrees Fahrenheit seems to be the make or break number for the babies; any lower than this temperature and the eggs may delay their hatching until hotter weather swings around. This means that colder months could be a better time to try and eradicate any silverfish issues you may have.

Silverfish Nymph Stage

After hatching, the babies are sort of like lobsters, in that they don’t grow their protective silvery scales for a few weeks, but once that takes place, they basically resemble the adult insects…just a lot smaller. Despite their size difference, silverfish in the adolescent nymph stage are really just as prolific and damaging as the adults when it comes to eating your published works and fine clothing.

Silverfish Adulthood

And of course, all bad things come to a grisly end: adulthood, in this case. Not much changes in the interim between nymph and adult, but the actual length of time it takes to mature can differ depending on environment and temperature issues.

Once they’ve reached maturity, though, a healthy silverfish living in ideal conditions can last an average three – six years, with ample opportunity to mate and procreate in that timespan… A worrying proposition for anybody with an infestation.

How do silverfish mate?

In terms of the actual mating process, silverfish sound more like shy pre-schoolers with a crush than any sort of serious life form trying to keep its existence relevant.

Silverfish fall into a small dance or ritual during reproduction which can take around half an hour (show offs) and is divided into three distinct phases…

The first phase is characterized by the male and female facing one another off and rubbing their antennae against each other’s – after a while, they begin to back off and then return to this position, like playing the lowest stakes game of chicken known to man.

The second phase sees the male fleeing from the chasing female… your guess is as good as mine.

In the third and final phase, the two lovers stand side by side, whilst the male vibrates his tail against the female, laying sperm capsules which the female absorbs into her body and fertilizes herself with.

Coming soon to a theatre near you, the rom-com for the ages.

And now we come to the end of our silverfish roadmap – with any luck, you’ll now be better informed when it comes to ridding your home of the silver non-fish that’s been chewing all your books.